The present invention disclosed herein relates to a bit stream processor, and more particularly, to a bit stream processor using a reduced table lookup.
An exclusive hardware or a general purpose embedded processor is used for bit stream coding such as a variable length code (VLC) or context-adaptive binary arithmetic coding (CABAC). The exclusive hardware is optimized for one standard format. Therefore, the exclusive hardware is not capable of processing various standard formats and the general purpose embedded processor is designed suitable for processing a fixed bit. That is, a general processor requires several registers for combining or dividing codes, or storing a position of the VLC when there is bit stream coding for processing variable length data. Therefore, the general processor becomes inefficient since several steps of instructions are required for bit stream coding. Additionally, the general processor uses a table lookup method for conversion between a VLC and a fixed length code. However, a table size is increased when an entropy code of a variable length is used in the table lookup method.